Sulfide stress cracking resistant drill pipe addresses h2s challenges. Which alloy is for sulfide stress and stress corrosion. Sulfide stress cracking ssc is a form of hydrogen embrittlement which is a cathodic cracking mechanism. Standard material requirements sulfide stress cracking. H 2 s can cause sulfide stress cracking of stainless steels. Sulfide stress cracking is the cracking of a metal under the combined action of tensile stress and corrosion in the presence of water and hydrogen sulfide a form of hydrogen stress cracking. This article describes current industry practices to catalog features observed after sulfide stress cracking testing.
Scc is defined as the brittle fracture of a normally ductile metal by the conjoint action of a specific corrosive environment and a tensile stress. But, the presence of h 2 s in well fluids imposes severe restrictions on the use of tubular goods due to sulfide stress cracking phenomenon 2. Sulfide stress cracking mostly occurs in very highly acidic environments. It can lead to unexpected sudden failure of normally ductile metal alloys subjected to a tensile stress, especially at elevated temperature.
This term should not be confused with stress corrosion cracking scs, since this is anodic in nature. Ian sutton, in plant design and operations second edition, 2017. No matter how well these pipelines are designed, constructed and protected, once in place they are subjected to environmental abuse, external damage, coating disbondments, inherent mill defects, soil movementsinstability and third party damage. The pipeline rehabilitation and replacement costs are included in. After the hydrotest, the next stage is to dry the pipeline to ensure that no water remains on the internal pipe wall or at low spots along the pipe route.
Sulfide stress cracking nace mr01752002, mr0175iso 15156 651 te c h n i c a l new sulfide stress cracking standard for refineries don bush, principal engineer materials, at emerson process management fisher valves, is a member and former chair of a nace task group that has written a document for refinery applications, nace mr0103. Corrosion investigation of pipeline steel in hydrogen sulfide containing solutions. Litigation support includes supervising laboratory testing, simulations, corrosion damage investigation, preparing. Sulfide stress cracking an overview sciencedirect topics. In this chapter the terms eac and scc are generally interchangeable. However, in some cases reported as 10 to 20 percent in canada scc also occurs in the circumferential direction cscc when the predominant stress is an axial stress, such as stresses developed in response to pipe.
Standard material requirements materials resistant to. Prepare and maintain core metallurgical, material, and quality control specifications for pipe. There are maximum acceptable h 2 s concentration limits in sale quality oil and gas, which require. Sulfide stress cracking ssc was first identified and the mechanism outlined in the 1940s after several failures of oil and gas systems in texas and canada. Sulfide stress corrosion cracking and hydrogen induced cracking of a216wcc wellhead flow control valve body article pdf available in case studies in engineering failure analysis. These cracks are not visible initially, but as time passes, these individual cracks may grow and forms colonies, and many of them join together to form longer cracks. Amine cracking is a form of stress corrosion cracking, which is related to alkaline and carbonate stress corrosion cracking. Safety, reliability and risks associated with water, oil and gas pipelines, pluvinage, g. Pdf sulfide stress corrosion cracking and hydrogen. What is nace mr0175iso 15156 steel pipe and fittings. When placed in proximity to tensile stresses, embrittlement and the beginnings of brittle fracture may occur. Jul 17, 2017 stress corrosion cracking in pipelines begins when small cracks develop on the external surface of buried pipelines. In order to ensure smooth and uninterrupted flow of oil and gas to the end users, it is imperative for the field operators, pipeline engineers, and designers to be corrosion conscious as the lines and their component fittings would undergo material degradations due to corrosion. Sulfide stress cracking how is sulfide stress cracking abbreviated.
What causes stress corrosion cracking in pipelines. Pdf sulfide stress corrosion cracking and hydrogen induced. Hydrogen sulfide burns with a blue flame to form sulfur dioxide which is. Sep 27, 20 in order to ensure smooth and uninterrupted flow of oil and gas to the end users, it is imperative for the field operators, pipeline engineers, and designers to be corrosion conscious as the lines and their component fittings would undergo material degradations due to corrosion.
Explains why pipeline stress corrosion cracking happens and how it can be prevented. Actuator sizing, standards and specifications for floating. Materials and corrosion trends in offshore and subsea oil. Corrosion problems during oil and gas production and its. As shown in figure 11, corrosion has been responsible for 18 percent of the significant incidents both. No matter how well these pipelines are designed, constructed and protected, once in place they are subjected to environmental abuse, external damage, coating disbondments, inherent mill.
Hydrogen sulfide is an extremely toxic, flammable gas that may be encountered in the production of gas well gas, highsulfide, high sulfur content crude oil, crude oil fractions, associated gas, and waters. Hydrogen cracking its causes, costs and future occurrence p h m hart weld metal hydrogen cracking in pipeline girth welds, proc. Amine cracking typically occurs on the surface and the cracks are usually radially. Hydrogen sulfide stress corrosion cracking in materials. The explosion caused a 35metre long, ninemetre deep crater after the pipeline was ejected from the ground, and the ruptured ends of the pipeline showed signs of tearing and heat exposure, the. Stress corrosion fact sheet pipeline risk management.
This standard nace mr0175iso 15156 addresses all mechanisms of cracking that can be caused by h2s, including below cracking conditions. The pipeline operator had a stress corrosion cracking hazard management plan in place for this pipeline. Sulfide stress cracking is the worst type of corrosion in the presence of hydrogen sulfide. Materials and corrosion trends in offshore and subsea oil and. Standard material requirements materials resistant to sulfide. Donner summit, ca, pipeline leakinvestigated a diesel and gasoline pipeline leak that occurred in an environmentally sensitive area in the sierra mountains, near donner lake, and the role that external damage and subsequent stress corrosion cracking may have played in the leak. Stress corrosion cracking scc is a type of environmentallyassisted cracking eac, or the formation of cracks caused by various factors combined with the environment surrounding the pipeline. Stress corrosion cracking scc a particularly detrimental form of pipeline corrosion is known as stress corrosion cracking scc. Scc occurs as a result of a combination between corrosion and tensile stress.
Oct 24, 20 sulfide stress cracking resistant drill pipe addresses h2s challenges. Stress corrosion cracking led to pipeline rupture in prince george. Susceptible alloys, especially steels, react with hydrogen sulfide, forming metal sulfides and atomic hydrogen as corrosion byproducts. Jul 25, 2017 most of the early failures were associated with sulfide stress cracking ssc, at the time a relatively new phenomenon. Be observant for signs of pipeline damage, leakage, or security concerns. Hydrogen embrittlement characteristics, especially pertinent to sulfide stress cracking, or steels has been investigated to a great extent. Sulfide stress cracking how is sulfide stress cracking. Is sulfide stress cracking an anodic or a cathodic process. Hydrogen cracking its causes, costs and future occurrence. Specialized stress corrosion cracking testing capabilities.
The influence of chemical composition and microstructure of api linepipe steels on hydrogen induced cracking and sulfide stress corrosion cracking. Hic and ssc behavior of highstrength pipeline steels. Pdf with the development of the natural gas industry, gas transmission pipelines have been developed rapidly in terms of safety, economy. Environmental cracking in line pipe carrying sour product. Corrosion is related to the susceptibility of the material to the environment, while stresses may be residual, external. In one such instance the pipeline in the subject case gave a service life of about 12 years in sour gas service. Aug 14, 20 carneiro r a, ratnapuli r c and lins v f c l. In the gas phase, a stream is sour if the h2s partial pressure exceeds 0. Pdf stress corrosion cracking of gas pipeline steels of different.
Home which alloy is best to resist sulfide stress cracking and stress. Sulfide stress cracking ssc of high strength, low alloy steel is a phenomenon of particular. Sulfide stress crackingresistant drill pipe addresses h2s. Sulfide stress cracking nace mr01752002, mr0175iso 15156.
Summary sulfide stress cracking ssc is just one of several forms of hydrogen. Experimental study of gas explosions in hydrogen sulfide. One of the corrosive environments under scrutiny is the stagnant floor water rich in sulfide and hydroxide due to their high solubility, which may form on the boiler floor during shutdown. Initiation of stress corrosion cracking and hydrogeninduced cracking in oil and gas linepipe steels. In this respect, the behavior in sour environment of the constitutive steels is an important parameter. An explosion and fire in 2018 along an enbridge inc natural gas pipeline in northern british columbia was caused by normal stress that. It should not be confused with the term stress corrosion cracking which is an anodic cracking mechanism. Strain and sulfide stress cracking in pipeline girth welds. This paper describes work performed under a short study programme into the sulfide stress corrosion cracking behaviour of samples taken from a pipe girth weld that were strained to conditions that simulated those of a typical pipe reeling and laying operation.
The major hazards of h 2 s are its ability to cause rapid damage to health or sudden death due to accidental exposure and metal integrity failure due to general corrosion or cracking. Corrosion investigation of pipeline steel in hydrogen sulfide. Wet hydrogen sulfide h2s cracking inspectioneering. But when they failed they failed catastrophically and sometimes repeated failures occurred. Metallurgy failure analysis and expert testimony introduction. The flixborough explosion was the largestever peacetime explosion in the uk. The gas can cause severe stress cracking of steel and other metals. Standard material requirements sulfide stress cracking resistant metallic materials for oilfield equipment contents 1. Since hydrogen sulfide is heavier than air, it can collect in low places. This is a complex topic, other factors, such as ph, chloride concentration, and temperature also affect the potential for steel cracking. The article also introduces a quantitative criterion to determine the maximum allowable defect size based on fracture mechanics principles. Sulphide stress cracking is prevented by minimising the hardness and strength of the. Scc cracking is usually oriented longitudinally in response to the hoop stress of the pipe, which is usually the dominant stress component resulting from the internal pressure. Most of the early failures were associated with sulfide stress cracking ssc, at the time a relatively new phenomenon.
Deficiencies in predicting the extent of cracking of the 36inch natural gas pipeline operated by westcoast energy inc. Sulfide stress cracking ssc occurs at locations where atomic hydrogen is able to diffuse at sites of high internal stress, such as grain boundaries, inclusions and regions of triaxial stress at notches. The steels sscc susceptibility was determined by constant load tensile according to nace tm0177 standard. It is appreciated that a material used in an h2s corrosive medium can suffer sulfide stress cracking ssc, a form of hydrogen embrittlement cracking occurring in h2s environments. Balon valves contain grease and are not suitable for oxygen service due to an increased risk of combustion or explosion. February 19, 2017 by mariano iannuzzi in a previous post, we discussed the broad differences between anodic and cathodic forms of environmentally assisted cracking eac. Which alloy is best to resist sulfide stress cracking and stress corrosion cracking. Stress corrosion cracking scc is the growth of crack formation in a corrosive environment. Sulfide stress cracking nace mr01752002, mr0175iso. Corrosion, stress cracking to blame for prince george pipeline fire in. By implementing the requirements of the regulation and through responsible maintenance programs, pipeline operators continuously inspect their pipelines for indications of scc. Sulfide stress cracking ssc vs hydrogen induced cracking hlc posted in refining, hydrocarbons, oil, and gas. Environmentally assisted cracking eac is a general term that includes processes such as stress corrosion cracking scc, hydrogen embrittlement he, sulfide stress cracking ssc, liquid metal embrittlement lme, and corrosion fatigue cf.
Scc is highly chemically specific in that certain alloys are likely to undergo scc only when exposed to a small number of chemical environments. Corrosionpedia what is sulfide stress cracking ssc. Sulfide stress cracking oil and gas pipelines wiley online library. Among the most prone to sulfide stress cracking include valve trim, blowout preventer hard parts and tool joints. H2s can cause sulfide stress cracking of stainless steels. Biaxial stress corrosion cracking frames capable of conducting testing in aggressive environments, such as brines with co 2 and h 2 s. Ssc is a form of spontaneous brittle breakdown in occurring in highstrength alloys and steels when it comes in contact with humid hydrogen sulfide as well as sulfidic atmospheres. When they are in good working order, they deliver fuel to meet the evergrowing demand for energy around the world. An experimental study of turbulent combustion of hydrogen sulfide h 2 s and natural gas was performed to provide reference data for verification of cfd codes and direct comparison. Pipeline failure rates from stress corrosion cracking.
Saeid kakooei, hossein taheri, mokhtar che ismail and abolghasem dolati, 2012. Sulfide stress cracking is a form of hydrogen embrittlement that occurs in highstrength steels and in localized hard zones in weldment of susceptible materials when the environment contains wet h 2 s. Investigations of hydrogen embrittlement and sulfide stress cracking of nickel and nickelbase alloys have not been quite as extensive as in the case of steels. Chapter 1 pipeline corrosion november 2008 page 1 1 introduction. Hydrogen sulfide is a colorless, very poisonous, flammable gas with the characteristic foul odor of rotten eggs. Liquid releases resulting in an unintentional fire or explosion. Stress, corrosion caused 2018 enbridge gas pipeline blast reuters. Sulfide stress crackingresistant drill pipe addresses h2s challenges.
Pipeline scc creates weaknesses at points in the pipe, which in turn makes the pipe more susceptible to third party damage, overpressure events, etc. Sulfide stress cracking is also called hydrogen sulfide cracking, sulfide cracking, sulfide corrosion cracking and sulfide stress corrosion cracking. Stress corrosion cracking led to 2018 pipeline explosion near prince. The catastrophic explosion at flixborough in june 1974 has been traced to the failure of a bypass. In this study, hydrogeninduced cracking hic and sulfide stress corrosion cracking ssc behaviors of highstrength pipeline steels in four different strength grades x70, x80, x90 and x100 with the microstructure of acicular ferrite were estimated. There were 28 fatalities as well as the near complete destruction of the nypro plant in north lincolnshire by blast and then fire. Micro alloyed pipeline steels are commonly used in the petroleum industry for transport applications 1. As we know that both form of cracking are due to the absorption of atomic hydrogen that is produced by. In year 2012 the pipeline failed suddenly by cracking along the heat affected zone of the spiral weld.
Sulfide stress cracking ssc stress corrosion cracking. This paper analyzed the hsla pipeline steels stress corrosion behavior and mechanism which tested in the saturated solution of h2s. Field observations and laboratory data have indicated that the stress corrosion cracking of composite tubes occurs predominantly during the boiler shutdown. Corrosion investigation of pipeline steel in hydrogen. Stress corrosion cracking found to be cause of 2018 pipeline. Stress corrosion cracking led to a pipeline explosion near prince george two years ago, according to a transportation safety board investigation. Sulfide stress cracking and corrosion fatigue of steels. Which alloy is for sulfide stress and stress corrosion cracking. The failure was classified as circumferential stress. For this reason, along with toxicity risks of hydrogen sulfide gas, it is essential that water muds be kept entirely free of soluble sulfides and especially hydrogen sulfide at low ph. Sulfide stress cracking is also called hydrogen sulfide cracking, sulfide cracking, sulfide corrosion cracking and. Amine cracking is often intertwined with wet hydrogen sulfide h 2 s and carbonate cracking, as amines, carbonates and wet sulfides often exist together in amine treating systems. Test frames for applying cyclic loads with the measurement of crack propagation rates.